#include <stdio.h>

struct Node;
typedef struct Node *PrtToNode;
typedef PrtToNode List;
typedef PrtToNode Position;

struct Node
{
    int Element;
    Position Next;
};

int IsEmpty( List L)
{
    return L -> Next == NULL;
}

int IsLast( Position P, List L )
{
    return P ->Next ==NULL;
}

Position Find( int X, List L )
{
    Position P;

    P = L ->Next;
    while ( P != NULL && P ->Element != X)
        P = P  ->Next;
    return P;
}

int main()
{
    return 0;
}